Question 43
On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, a white precipitate is obtained.
(a) Write a balanced chemical equation of the reaction involved.
(b) What other name can be given to this precipitation reaction?
(c) On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?
Question 43
On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, a white precipitate is obtained.
(a) Write a balanced chemical equation of the reaction involved.
(b) What other name can be given to this precipitation reaction?
(c) On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?
a) Balanced chemical equation:
BaCl2(aq) + Na2SO3(aq) ⟶ BaSO3(s) + 2NaCl(aq)
Barium chloride Sodium sulphite Barium sulphite Sodium chloride
(white ppt.)
(b) This reaction is also known as a double displacement reaction as both reactants exchange their ions.
(c) BaSO3 when treated with dilute HCl forms barium chloride and liberates sulphur dioxide gas which has a characteristic odour of burning sulphur. The reaction occurs as follows:
BaSO3(s) + 2HCl (aq) → BaCl2(aq) + H2O(l) + SO2(g)
Barium sulphite Hydrochloric acid Barium chloride Water Sulphur dioxide
(white)
Since, BaCl2 is water-soluble, the white precipitate disappears.
a) Balanced chemical equation:
BaCl2(aq) + Na2SO3(aq) ⟶ BaSO3(s) + 2NaCl(aq)
Barium chloride Sodium sulphite Barium sulphite Sodium chloride
(white ppt.)
(b) This reaction is also known as a double displacement reaction as both reactants exchange their ions.
(c) BaSO3 when treated with dilute HCl forms barium chloride and liberates sulphur dioxide gas which has a characteristic odour of burning sulphur. The reaction occurs as follows:
BaSO3(s) + 2HCl (aq) → BaCl2(aq) + H2O(l) + SO2(g)
Barium sulphite Hydrochloric acid Barium chloride Water Sulphur dioxide
(white)
Since, BaCl2 is water-soluble, the white precipitate disappears.
